Final answer:
Meselson and Stahl experiments confirmed the semiconservative model of DNA replication, in which each new DNA molecule contains one original and one new strand.
Step-by-step explanation:
Matthew Meselson and Franklin Stahl provided evidence for the semiconservative model of DNA replication in bacteria. In their experiment, they utilized isotopes of nitrogen, 15N and 14N, to label the DNA in E. coli cells. After one generation of growth in a medium with 14N, the DNA showed a single band of intermediate density, ruling out a conservative replication model. In the subsequent generation, two bands were observed: one band of intermediate density and another corresponding to 14N DNA. This pattern of DNA bands after two generations of growth supported the semiconservative model, where each daughter DNA molecule consists of one old strand and one newly synthesized strand.